Method and apparatus for reducing radiation induced change in semiconductor structures

ABSTRACT

Embodiments of the present disclosure relate to an apparatus and a method for reducing the adverse effects of exposing portions of an integrated circuit (IC) device to various forms of radiation during one or more operations found within the IC formation processing sequence by controlling the environment surrounding and temperature of an IC device during one or more parts of the IC formation processing sequence. The provided energy may include the delivery of radiation to a surface of a formed or a partially formed IC device during a deposition, etching, inspection or post-processing process operation. In some embodiments of the disclosure, the temperature of the substrate on which the IC device is formed is controlled to a temperature that is below room temperature (e.g., &lt;20° C.) during the one or more parts of the IC formation processing sequence.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/075,094 filed on Mar. 18, 2016, which claims benefit of U.S.provisional patent application Ser. No. 62/135,476, filed Mar. 19, 2015,which are both hereby incorporated herein by reference.

BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

Embodiments of the present disclosure generally relate to thefabrication of integrated circuits and particularly to an apparatus andmethod for reducing change created within semiconductor devices due totheir exposure to various types of radiation during a formation orinspection process.

Description of the Related Art

The integrated circuit (IC) market is continually demanding greatermemory capacity, faster switching speeds, and smaller feature sizes.Reducing the size of integrated circuits (ICs) results in improvedperformance, increased capacity and/or reduced cost. Each sizereduction, or IC processing node shift, requires more sophisticatedtechniques to form the various components within the ICs. As IC devicesbecome smaller the physical integrity and dimensional stability ofstructures formed within the IC device becomes much more challenging toreliably maintain when they are exposed to various forms of radiationprovided energy during typical IC forming and inspection processes. Forexample, photolithography and etching processes are commonly used topattern various layers formed in the IC device, such as a photoresistlayer, spin-on-carbon (SOC) layer, BARC layer and hard mask layers. Theexposure of these various layers to the energy generated during thephotolithography and etching operations, such as RF energy andelectromagnetic radiation used during inspection or post-processingoperations can alter, change or adversely affect the properties of theformed IC layers and structures.

One aspect of the IC device structure that can be readily affectedduring the IC fabrication process, due to the exposure to one or moreforms of energy, is line width roughness (LWR) or line edge roughness(LER) that are created in a photolithographic process. As known in theart, LWR is defined as the excessive variations in the width of thepatterned photoresist feature formed after the unexposed portions of thephotoresist are stripped from the substrate in, for example, a negativeresist type lithography process. If the variations occur on the sidesurface of the photoresist relief or feature the variation is known asLER. An increase in roughness or variations in LWR or LER due to theexposure to various forms of energy during processing isdisadvantageous, as the increased roughness variation may be transferredonto various features during the subsequent etching process, and thusultimately into the formed IC circuit. The variations become moresignificant as the feature size of the photoresist relief or trenches isdecreased. For 32 nm devices variations of 4 nm or larger have beenobserved. Because the geometrical shape of a patterned resist feature,including line roughness effects (e.g., LWR and LER), is transferredfrom a patterned photoresist layer to an underlying permanent layer of adevice during patterning of the underlying layer, LWR and LER can limitthe ability to form devices of acceptable quality for dimensions belowabout 100 nm. Such variations may lead to non-uniform circuits andultimately device degradation or failure.

Therefore, as devices shrink to smaller dimensions, current ICfabrication processes are challenged to create devices that can beformed with the required physical and structural properties, and desiredcritical dimensions (CD). Therefore, there is a need for new apparatusesand methods that can reduce the damaging effects of radiation providedduring an IC fabrication process on the physical properties, electricalproperties and dimensional stability of structures formed within an ICon a substrate.

SUMMARY OF THE DISCLOSURE

Embodiments of the present disclosure relate to an apparatus and amethod for reducing the adverse effects of exposing portions of anintegrated circuit (IC) device to various forms of radiation during anIC formation processing sequence that may include a depositionoperation, an etching operation, an ashing operation, an annealingoperation, an inspection operation and/or a post-processing processoperation. In some embodiments of the disclosure, the temperature of thesubstrate on which the IC device is formed is controlled to atemperature that is below the preprocessing temperature of thesubstrate, such as room temperature.

Embodiments of the disclosure provide a method of inspecting a surfaceof a substrate, comprising positioning a substrate on a substratesupport assembly that is maintained at a temperature that is less than20° C., exposing a region of a surface of the chucked substrate to anamount of radiation, wherein the exposed region achieves a first peaktemperature due to the exposure to the amount of radiation, and thefirst peak temperature is less than a threshold temperature for allmaterials in the exposed region. The substrate may be chucked to thesubstrate supporting surface of the substrate support assembly, whereinthe substrate support surface is maintained at a temperature that isless than 20° C., such as a temperature less than 0° C., or even atemperature of between −30° C. and −100° C.

Embodiments of the disclosure may further provide a substrate inspectionapparatus, comprising a process chamber defining a processing region, asubstrate support comprising a substrate chuck that has a substratesupporting surface that is disposed within the processing region, aradiation source that is configured to deliver radiation towards thesubstrate supporting surface of the substrate support, a supportassembly that comprises one or more actuators that are configured totranslate the substrate support and substrate chuck relative to theradiation source, a temperature control assembly that is in thermalcommunication with the substrate supporting surface, wherein thetemperature control assembly is configured to cool the substratesupporting surface to a first temperature that is less than 20° C.; anda radiation detector configured to detect radiation reflected orscattered from a surface of a substrate that is disposed on thesubstrate supporting surface of the substrate support during aninspection process performed in the process chamber.

Embodiments of the disclosure may further provide a method of inspectinga surface of a substrate, comprising positioning a substrate on asubstrate support assembly in a process chamber, the process chamberlocated in a first environment, wherein positioning the substratecomprises chucking the substrate to a substrate supporting surface of asubstrate support assembly, wherein the substrate supporting surface iscooled to a temperature less than 0° C. The method further comprisingexposing a region of a surface of the chucked substrate to radiation,wherein the exposed region achieves a first peak temperature due to theexposure to the radiation, wherein the first peak temperature is lessthan 150° C. The method further comprising maintaining the temperatureof the substrate supporting surface at less than 0° C. during theexposure of the surface of the chucked substrate to the radiation.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1A illustrates a cross-sectional view of a patterned structureformed on substrate, according to an embodiment of the disclosure.

FIG. 1B is a graph depicting the effect of exposing a semiconductorstructure formed on substrate to an increasing amount of energy duringone or more operations within a semiconductor fabrication process,according to one embodiment of the disclosure.

FIG. 1C is a graph depicting an amount of energy that is provided to theexposed region of the semiconductor structure due to the delivery of theradiation provided from a radiation source as a function of time,according to one embodiment of the disclosure.

FIG. 1D illustrates a cross-sectional view that illustrates the exposedportions of the patterned structure shown in FIG. 1A after being exposedto the radiation “A”, according to an embodiment of the disclosure.

FIG. 1E is a graph depicting a temperature rise of an IC structureformed on a substrate based the delivery of an amount of radiation and atemperature rise of the same IC structure that is exposed to same amountof radiation when using one or more of the exemplary methods andapparatuses disclosed herein.

FIG. 2 is an isometric partial cross-sectional view of a processchamber, according to an embodiment of the disclosure.

FIG. 3 is an isometric partial cross-sectional view of a stage assemblythat may be used in the process chamber shown in FIG. 2, according to anembodiment of the disclosure.

FIG. 4 is a side cross-sectional view of a substrate support that may beused in the process chamber shown in FIGS. 2 and 3, according to anembodiment of the disclosure.

FIG. 5 is a flowchart depicting a processing sequence that is performedin a process chamber, according to embodiments described herein.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation.

DETAILED DESCRIPTION

Embodiments of the present disclosure relate to an apparatus and amethod for reducing the adverse effects that may occur when exposingportions of an integrated circuit (IC) device to various forms of energyduring one or more operations found within an IC formation processingsequence by controlling the environment surrounding and temperature ofthe IC device during the one or more operations. The provided energy mayinclude the delivery of radiation to a surface of a formed or apartially formed IC device during a deposition, etching, inspection orpost-processing process operation. In some embodiments of thedisclosure, the temperature of the substrate on which the IC device isformed is controlled to a temperature that is below room temperature(e.g., <20° C.) during one or more parts of the IC formation processingsequence.

In one example, a method and apparatus is used to reduce the adverseeffects of exposing portions of patterned regions of an IC device toradiation during one or more semiconductor processing operations used topattern, inspect and/or form the IC device. FIG. 1A illustrates aportion of an IC device 10 that has been patterned by use of an opticallithography technique to form a plurality of patterned regions. Thepatterned regions may be formed using one or more optical lithographyprocesses to generate a patterned structure 110 in one or more of theunderlying layers 104. During an optical lithography process, thesurface 105 of a substrate 102 is finally coated with photo-curable,polymeric photoresist 115 after certain patterning or other films aredeposited. The polymeric photoresist 115 is then optically patternedusing a stepper, and then developed and baked at temperatures less thanabout 150° C. to form the patterned structure 110, as shown in FIG. 1A.The patterned photoresist layer contains a polymeric photoresist 115material that has gone through a plurality of photolithographyprocessing operations, such as a resist coating operation, soft bakeoperation (e.g., bake at temperature of 120° C. for 60 seconds),exposure operation, post exposure bake (PEB) operation (e.g., bake attemperature of 110° C. for 60 seconds), develop operation and then ahard bake operation (e.g., bake at temperature of 150° C. for 60seconds). In some configurations, the patterned structure 110 mayinclude a polymeric photoresist 115 and one or more additionalpatterning layers 116. The one or more additional patterning layers 116may include a spin-on-carbon (SOC) layer, BARC layer and/or one or morehardmask layers. Next, during an etching process, the pattern formed inthe patterned structure 110 can be transferred to the underlying layers104 below, by etching the exposed regions of the underlying layers 104.The underlying layers 104 may include portions of one or more hard masklayers, dielectric layers and/or device film layers that are to bepatterned. The often physically and dimensionally fragile componentsformed in the patterned structure 110 may also be further processedusing one or more additional semiconductor processing operations.

In general, the additional semiconductor processing operations mayinclude the delivery of radiation to the surface of a substrate during adeposition, etching, ashing, thermal processing, inspection and/orpost-processing process operation, as discussed above. In one example,during an inspection process the patterned structure 110 and exposedportions of the substrate 102 are exposed to a form of radiation “A”that is used to determine some physical property, material property orother compositional, dimensional or defect related attribute of thesurface of the substrate 102. Inspection processes will generallyinclude one or more IC device metrology inspection operations, surfaceimaging operations, defect inspection operations and/or materialcharacterization inspection operations. During these inspectionprocesses the radiation “A,” e.g., a probing beam or spot, may bedelivered to the exposed regions of the substrate 102 as a small areaspot that has an exposure area (e.g., illuminated area) that issignificantly smaller than the surface of the substrate 102. In thistype of inspection process, the small area spot is scanned across thesurface of the substrate 102 to determine a property of the substrate102. In one example, the small area spot may have an area of betweenabout 0.1 square micrometer (μm²) to about 10 μm². Alternately, theradiation “A,” or probing beam, may be a large area beam that “floods”at least a large portion of the surface of the substrate 102. In oneexample, the small area spot may have an area of between about 0.1square millimeter (mm²) and about 10 mm². In either case, the radiation“A,” or probing beam, may be provided to the substrate 102 aselectromagnetic radiation, an electron beam or an ion beam. In caseswhere the radiation “A” includes electromagnetic radiation, theradiation may be a form of coherent or non-coherent radiation that maybe delivered as a continuous wave (CW) of electromagnetic energy or aspulses of electromagnetic energy.

Since the delivery of a probing beam or spot to a surface of thesubstrate may change or affect the properties of the exposed layers,embodiments of the present disclosure may be advantageously used toprevent the exposed surfaces of a formed or a partially formed ICstructure from becoming altered or undesirably changed. Embodimentsdisclosed herein can be advantageously used to prevent portions of an ICstructure from being changed during an inspection process. In general,the inspection processing operations are not intended to modify theinspected structures formed on the substrate surface. However, due tothe shrinking size of the IC devices, and the use of layers within thesestructures that have optically absorbing and thermally insulatingproperties, the use of a probing beam of radiation during an inspectionoperation can increase the temperature of the probed region to a pointwhere the film layers can become changed. For example, inspectionsystems using ultraviolet (UV) and/or deep UV wavelength beam(s) thatare delivered at typical inspection power levels may increase thetemperature of 32 nm advanced IC patterned structures which mayundesirably cause changes to the materials in these structures. Thus, insome embodiments, the temperature of a partially formed IC structure iscontrolled, during an inspection processing operation, to a temperaturethat is less than the temperature of the substrate before the process,such as room temperature. The temperature at which the substrate ismaintained may be less than zero degrees Celsius to prevent change fromoccurring in the exposed film layers.

FIG. 1B is a plot of the effect of exposing a region of a patternedstructure to an increasing amount of incident radiation power (energy)on line-edge-roughness (LER), as illustrated by line 121, during one ormore operations within an optical inspection process. FIG. 1C is a plotof power exposure (e.g., curve 131) as a function of time provided tothe portion of the patterned structure 110 by the incident radiation.The amount of energy 132 provided to a region of the substrate 102 is afunction of the integrated incident power (energy) provided over theexposure interval (e.g., time between time T₀ and time T₁), which is thearea under the curve 131. The amount of incident power directly affectsthe temperature rise of the probed IC device, which can affect theamount of change or undesirable effects of exposing the IC device to theprobing beam. The temperature rise created in the exposed structureswill generally increase as the percentage of radiation absorptionincreases, the size of the exposed features decreases and/or the time ofexposure, at a constant power level, decreases. As illustrated in FIG.1B, the delivery of radiation to the substrate 102 generally does nothave a detrimental effect on the physical, dimensional or materialproperties of the exposed regions until a threshold energy level, suchas a threshold power level P_(T) is reached. Thus, as illustrated inFIG. 1B, once the threshold incident radiation power level P_(T) hasbeen reached, a property of the exposed IC device can be dramaticallychanged, such as the LER of a photoresist pattern is dramaticallyincreased. In this example, the measured LER of a structure exposed toradiation that is below the threshold power level P_(T) is observed toremain at a relatively low level and at the peak power level P_(P) themeasured LER was almost doubled in magnitude. It is believed that thetemperatures achieved by the materials found within an exposed region,which has received radiation at levels greater than the threshold powerlevel P_(T), will reach a level that is greater than their materialdegradation temperature or change threshold temperature. In one example,photoresist materials are known to degrade at temperatures greater thanthe hard bake temperature (e.g., typically 150° C.), thus radiation thatis delivered to a photoresist material that cause its peak exposuretemperature to exceed the hard bake temperature will cause changes tothe photoresist material.

FIG. 1D illustrates a portion of an IC device 10 that includes variousexposed regions 160 that have been exposed to the radiation “A”. Thetemperature rise within and depth of the affected exposed regions 160will depend on the amount of energy provided by the radiation “A”, andthe physical, optical absorption and/or heat transfer related propertiesof the exposed materials and adjacent material layers. In someconfigurations, due to the optically transparent nature of the overlying layer(s), the radiation “A” can reach and be absorbed in one ormore of the underlying layers. In one example, exposed regions 161 areformed in portions of the underlying patterning layers 116 due to thedelivery of the radiation “A” to the IC device structure. Therefore, theeffect of the probing beam on the IC device will depend on theproperties of the delivered radiation (e.g., wavelength, power,duration, etc.) and the physical, material, thermal and opticalproperties of the exposed regions of the IC device formed on thesubstrate.

FIG. 1E illustrates a comparative example of the temperature risecreated in an IC device structure formed on a surface of a substratebased on the use of a conventional processing technique, which isillustrated as temperature rise 196, and a temperature rise 197 createdin the same device structure that is processed using one of theprocessing techniques described herein. In the conventional processingtechnique example, the substrate is provided at a conventional processstarting temperature, which in this example is assumed to be about roomtemperature T_(R). Therefore, based on the size of the device structure,thermal and optical properties of the exposed regions of the devicestructure and the energy provided by the radiation delivered to thedevice structure, the temperature rise (ΔT) will equal T₃ minus T_(R),where T₃ is the peak temperature of the exposed components in the devicestructure. However, it is believed that the peak temperature T₃ achievedusing some conventional processing techniques can exceed a temperaturethat will change the physical or electrical properties of one or morematerials within the exposed IC device structure.

In an effort to prevent a formed or partially formed IC device frombecoming changed during processing, in some embodiments, the substrateis cooled to a first processing temperature T₁, which is less than 20°C., such as a temperature between about −30° C. and −100° C. In thiscase, the device structure will achieve a temperature rise that is equalto the second temperature T₂ minus the first temperature T₁, where thesecond temperature T₂ is the peak temperature of the exposed componentsin the device structure. In general, the first temperature T₁ iscontrolled by use of the hardware components described below so that thesecond temperature T₂ is lower than a temperature at which the materialsin the IC device structure will become changed by the delivery of theincident radiation, which is illustrated as temperature T_(M) in FIG.1E. In one example, the first temperature T₁ is controlled to a level,such that the temperature rise 197, does not allow a photoresistmaterial on the surface of the substrate to exceed the photoresist hardbake temperature (e.g., second temperature T₂≤150° C.).

Hardware and Process Chamber Configuration Examples

FIG. 2 illustrates an isometric cross-sectional view of a processchamber 200 that is configured to control the temperature of at least aportion of a substrate 210 that is exposed to radiation delivered from asource 230, during one or more parts of the IC formation processingsequence. The process chamber 200 generally includes a substrateenclosure 201, a substrate support assembly 250, a temperature controlassembly 215, a system controller 290, a gas delivery system 206 and anexhaust system 205. The substrate enclosure 201 generally includes aplurality of walls 203 that enclose a processing region 211. In someconfigurations, a window (not shown) is formed in or through one of thewalls 203, which is disposed over the surface 213 of the substrate 210,to allow the radiation generated by a source 230, which is disposedoutside of the substrate enclosure 201, to be delivered to an exposedregion 231 of the substrate 210. The source 230 is adapted to provideradiation “A,” which, as discussed above, may include electromagneticradiation, an electron beam or an ion beam.

The substrate enclosure 201 may also include a sealable port 202 thatallows a user or a robotic device (not shown) positioned outside of thesubstrate enclosure 201 to position a substrate 210 at a desiredlocation within the process chamber 200. The sealable port 202 mayinclude a slit valve (not shown) or other similar device that is adaptedto prevent gases from passing between a region outside of the substrateenclosure 201 and the processing region 211 when the sealable port 202is sealed.

The substrate support assembly 250 generally includes a support assembly214 and an actuation assembly 217 that is adapted to move and/orposition a substrate 210, which is disposed on a substrate supportingsurface of the support assembly 214, relative to the radiation deliveredfrom the source 230. The actuation assembly 217 may include one or moreactuators 217A, 217B that are adapted to move and/or position thesubstrate 210 in at least one direction (e.g., X-direction, Y-directionand/or Z-direction). The actuators 217A, 217B may be any type of devicethat is able to move and position the support assembly 214, such as alinear motor, stepper motor and lead-screw, or other similar device.

The temperature control assembly 215 generally includes components thatare able to control and maintain the temperature of the substrate 210during processing. In some configurations, the temperature controlassembly 215 may include a gas and/or liquid heat exchanger, Peltierdevice, or other similar device that is adapted to control thetemperature of a substrate supporting surface of a support device 220 inthe support assembly 214 to a desired temperature. The temperaturecontrol assembly 215 is generally adapted to control the temperature ofthe substrate supporting surface of the support device 220 by use ofcommands sent from the system controller 290. In one example, thesubstrate 210 is cooled to a temperature between about 20° C. and −195°C., such as between about 0° C. and about −100° C., or a temperaturebetween about −30° C. and about −100° C., or even to a temperaturebetween about −40° C. and about −100° C. using the temperature controlassembly 215 components. In this case, the reduced substrate temperaturecan be used to compensate for the temperature rise created by thedelivery of the radiation provided to the substrate 210 by the source230. Thus, the maximum temperature reached by the structures within theIC device formed on the substrate 210 during the processing operationcan be controlled so that the temperature does not exceed a maximumtemperature threshold level (e.g., temperature T_(M)) or changethreshold temperature, above which the layer will become changed, orphysically or chemically changed in some undesirable way, such asimpacting the functional properties of one or more materials in thelayer.

In some embodiments, if the substrate temperature during processing ismaintained at a temperature less than room temperature, it is desirableto control the composition of the gases that are found in the processingregion 211, so that no condensation or other undesirable contaminationwill form on the cooled substrate and exposed supporting componentsduring processing, such as the support assembly 214 components. In oneconfiguration, the substrate enclosure 201 includes an exhaust system205 that contains a pump 242 that is configured to evacuate and/orreduce the pressure within the processing region 211 during processingto remove any water or other contamination found therein. The pump 242may be coupled to the processing region through an outlet 244 that isattached to a wall 203 of the substrate enclosure 201. In someconfigurations, the substrate enclosure 201 may include a gas deliverysystem 206 that contains a gas source 207 that is configured to deliverone or more gases to the processing region 211 during processing toremove any water or other contamination found therein. In some cases,the gas delivery system 206 and the exhaust system 205 may be usedtogether so that any contaminants in the processing region 211 can beflushed out and/or removed from the process chamber 200. The gasdelivery system 206 may be configured to deliver a dry, inert and/ornon-reactive gas, such as nitrogen (N₂), argon (Ar), helium (He), neon(Ne), krypton (Kr), xenon (Xe), or other similar type of gas, andcombinations thereof.

In some embodiments, to prevent the cooled substrate 210 from adsorbingor condensing an amount of water or other contamination when thesubstrate 210 is positioned in an environment external to the processchamber 200 after processing, the process chamber 200 may additionallyinclude a heating station 260. The heating station 260 may include atemperature controlled substrate support assembly 262 that includes athermal control device 261 and a thermal controller 265. The thermalcontrol device 261 may include a gas or fluid heat exchanger and/or oneor more resistive heating elements (not shown) and thermocouples (notshown). The thermal control device 261 also includes a surface 261A onwhich the substrate 210 may be placed to adjust the substrate'stemperature before and/or after processing has been performed on thesubstrate 210 using the substrate support assembly 250. The thermalcontroller 265 is generally adapted to control the temperature of thesurface 261A of the thermal control device 261 by use of commands sentfrom the system controller 290. In some embodiments, the temperature ofthe surface 261A of the thermal control device 261 is maintained at atemperature greater than the dew point of an environment that is founddirectly outside of the process chamber 200 (e.g., the environmentsurrounding and contacting the external portions of the processchamber). In one example, the temperature of the surface 261A ismaintained at a temperature of between about 10° C. and 50° C. In someembodiments, the temperature of the surface 261A is maintained at atemperature less than room temperature, but greater than the dew pointof the environment outside the process chamber. In this case, thetemperature of the surface 261A of the thermal control device 261 willallow the temperature of the substrate 210 to be reduced before thesubstrate 210 is positioned on the colder substrate supporting surfacesof the substrate support assembly 250, so that the substrate 210 can berapidly processed in the process chamber 200, and also allow thesubstrate 210 to be heated to a temperature after processing on thesubstrate support assembly 250 to prevent the adsorption of contaminantson the surface of the substrate 210 when the substrate 210 is movedoutside of the process chamber 200.

In some embodiments of the heating station 260, the substrate may alsobe heated after being processed on the substrate support assembly 250 byuse of radiant source 295. The radiant source 295 may include one ormore lamps that are configured to rapidly and uniformly heat thesubstrate 210 positioned on the surface 261A of the heating station 260to a desired temperature before the substrate 210 is removed from theprocessing region 211 of the process chamber 200.

The system controller 290 is used to control one or more componentsfound in the process chamber 200. The system controller 290 is generallydesigned to facilitate the control and automation of the process chamber200 and typically includes a central processing unit (CPU) (not shown),memory (not shown), and support circuits (or I/O) (not shown). The CPUmay be one of any form of computer processors that are used inindustrial settings for controlling various system functions, substratemovement, chamber processes, and control support hardware (e.g.,sensors, internal and external robots, motors, radiation sources, lamps,etc.), and monitor the processes performed in the system (e.g.,substrate support temperature, chamber process time, I/O signals, etc.).The memory is connected to the CPU, and may be one or more of a readilyavailable memory, such as random access memory (RAM), read only memory(ROM), floppy disk, hard disk, or any other form of digital storage,local or remote. Software instructions and data can be coded and storedwithin the memory for instructing the CPU. The support circuits are alsoconnected to the CPU for supporting the processor in a conventionalmanner. The support circuits may include cache, power supplies, clockcircuits, input/output circuitry, subsystems, and the like. A program(or computer instructions) readable by the system controller 290determines which tasks are performable on a substrate in the processchamber 200. Preferably, the program is software readable by the systemcontroller 290 that includes code to perform tasks relating tomonitoring, execution and control of the movement, support, and/orpositioning of a substrate along with the various process recipe tasks(e.g., inspection operations, processing environment controls) andvarious chamber process recipe operations being performed in the processchamber 200.

In one embodiment of the process chamber 200, a robotic device 270 isconfigured to transfer a substrate 210 in either direction between theheating station 260 and the substrate support assembly 250. The roboticdevice 270 may include an upper robot arm 271, having a substratesupporting surface 272, and a lower arm 273 that are coupled togetherand to an actuator (not shown), so that the robotic device 270 cantransfer the substrate 210 within the processing region 211 of theprocess chamber 200 by use of commands from the system controller 290.The heating station 260 and the substrate support assembly 250 may eachinclude a substrate lifting device (not shown) that enables the roboticdevice 270 to handoff the substrate to each station.

FIG. 3 is an isometric view of one non-limiting example of the substratesupport assembly 250 illustrated in FIG. 2. FIG. 4 is a sidecross-sectional view of a support device 220 of the substrate supportassembly 250 along section line 4-4 in FIG. 3. In this example, thesubstrate support assembly 250 includes one or more temperaturecontrolling components and one or more translation enabling componentsthat allows the substrate to be moved and/or positioned relative to theradiation “A” provided by the source 230. However, in some embodiments,the source 230 is adapted to scan the radiation “A” relative to thesurface of a substrate that is positioned in a desired stationaryposition or is also being translated by the components in the substratesupport assembly 250.

As briefly discussed above, the substrate supporting components areadapted to support, position, and control the temperature of thesubstrate 210 that is positioned on a support device 220. In someembodiments, the substrate support assembly 250 may contain one or moreelectrical actuators 217A, 217B (e.g., linear motor, lead screw andservo motor) and one or more stages 218, which are used to control themovement and position of the substrate 210. The stages 218 may contain arotational element (not shown) that is able to support and rotate thesupport device 220 about the Z-axis and/or one or more linear slides 219that are used to guide and translate the various substrate supportingcomponents in at least one direction (e.g., X-direction and/orY-direction). In one embodiment, the movement of a support device 220that is positioned on the support assembly 214 in a Y-direction iscontrolled by use of an electrical actuator 217A and the movement of thesupport device 220 in an X-direction is controlled by use of anelectrical actuator 217B.

The temperature of the substrate during processing is controlled byplacing a substrate 210 in thermal contact with a substrate supportingsurface 415 (FIG. 4) of the support device 220. The substrate supportingsurface 415 is thermally controlled by use of one or more temperaturecontrolling components found in the substrate support assembly 250. Insome configurations, these temperature controlling components includethe temperature control assembly 215, which includes the supporttemperature control assembly 431, and may additionally include a heatexchanging device 241 (FIG. 3).

Referring to FIG. 4, in some embodiments, the support device 220 mayinclude a substrate chuck 410, base 420, temperature measuring element411 (e.g., thermocouple, RTD, etc.) and the temperature control assembly215. The base 420 is generally formed from a thermally conductivematerial, such as a metal or ceramic material (e.g., AlN). The base 420is positioned on the supporting surface 216 of the support assembly 214and is used to support the substrate 210 and substrate chuck 410.Portions of the base 420 are also used to transfer heat between asubstrate 210, positioned on the substrate chuck 410, and the supporttemperature control assembly 431 that is thermally coupled to the base420.

The substrate chuck 410 is generally formed from a thermally conductivematerial, such as a metal or ceramic material (e.g., AlN, SiC). Thesubstrate chuck 410 may contain a mono-polar or a bipolar electrostaticchucking electrode 412 that can be biased by a chucking power source 417so that an electrostatic chucking force can be provided to the substrate210. The act of applying an electrostatic chucking force to thesubstrate, or “chucking” the substrate, is used to assure that thesubstrate 210 is in good thermal contact with the substrate supportingsurface 415 of the support device 220. In some configurations, thesubstrate chuck 410 may include one or more grooves 413, which areformed in the substrate supporting surface 415 of the substrate chuck410, to allow a gas to be provided to the backside of the substrate toincrease the transfer of heat between the substrate 210 and the supportdevice 220, while the substrate is chucked. Alternately, in someconfigurations, the grooves 413 allow a vacuum chucking force to beapplied to the substrate 210 by use of a vacuum generating device 416that cause the substrate to be chucked to the substrate supportingsurface 415. In this case, the vacuum generating device 416 isconfigured to generate a low pressure within the grooves 413, which arepositioned adjacent to a region of the backside of the substrate 210, tocause the substrate 210 to be urged against the substrate supportingsurface 415 of the support device 220.

The support temperature control assembly 431 may include a gas and/orliquid heat exchanger, Peltier device, resistive elements or othersimilar device that is adapted to control the temperature of thesubstrate supporting surface 415 to a desired temperature. In oneconfiguration, the temperature control assembly 431 includes a lowtemperature chiller 421 that is configured to deliver a cooling fluidthrough channels 421A formed in the base 420. In one example, the lowtemperature chiller 421 is adapted to circulate a cooling fluid (e.g.,Galden HT55, liquid nitrogen, compressed helium, etc.) in the channels421A to cool the substrate 210 to a temperature of less than 20° C.,such as between about 0° C. and −100° C.

In some embodiments, the temperature control assembly 215 is alsoadapted to heat and/or cool the supporting surface 216 of the supportassembly 214 by use of the heat exchanging device 241. The heatexchanging device 241 may include a gas and/or liquid heat exchanger,resistive elements and/or other similar device that is adapted tocontrol the temperature of a supporting surface 216 to a desiredtemperature to provide an improved and more stable control of thetemperature of the base 420, substrate chuck 410 and substrate 210during processing. It is believed that the additional cooling of thesupporting surface 216 may help assure that the temperature of thesubstrate chuck 410 and substrate 210 are stable when the substrate ischilled to a low processing temperature, such as between −30 and −100°C. during processing. In one example, the heat exchanging device 241 isadapted to circulate a cooling fluid through channels 215B (FIG. 3) tocool the supporting surface 216 to a temperature of less than 20° C.,such as between about 0° C. and 10° C.

Referring back to FIG. 3, the process chamber 200 may include a source230 that is configured to provide electromagnetic radiation to anexposed region 231 on the surface of the substrate 210. In oneconfiguration, the source 230 includes a radiation source 301, ascanner/mirror 303, a beam splitter 305, an objective lens 307 and anoptional radiation detector 306. In some configurations, the radiationsource 301 is adapted to deliver an amount of coherent or non-coherentelectromagnetic radiation to the exposed region 231. In one example, theradiation source 301 is configured to deliver electromagnetic radiationin the infrared, visible, ultraviolet, deep ultra violet and/or extremedeep ultra violet electromagnetic radiation ranges. The objective lens307 is used to gather and focus the electromagnetic radiation producedby the radiation source 301, and may include a single lens or mirrors,or combinations of several optical elements. The scanner/mirror 303 maybe used to adjust the position of the exposed region 231 relative to thesurface of the substrate 210. In some configurations, the beam splitter305 may include a mirror, or reflective surface, which is adapted toredirect electromagnetic radiation reflected or scattered from thesurface of the substrate 210 to the optional radiation detector 306. Theradiation detector 306 is a conventional radiation detecting device thatis configured to detect the radiation reflected or scattered from thesurface of the substrate 210, due to the delivery of the radiation “A”provided from the radiation source 301.

In configurations where the process chamber 200 is adapted to perform awafer inspection type process, the radiation source 301 may operate at aDUV wavelength, for example 193 nm. In one example, the radiation source301 is configured to deliver electromagnetic radiation in a “flood” likemanner using a 2-D imaging sensor at a DUV wavelength to the exposedregion 231 at a power level of between about 0.1 and about 10 Watts (W)and an illuminated area of between about 0.1 and 10 mm².

In another configuration, where the process chamber 200 is adapted toperform a wafer inspection type process, the radiation source 301 mayoperate at a short wavelength, for example, 248 nm or 193 nm, in orderto produce a high resolution inspection technique that has a stableradiation source 301 output power (or stable pulse energy and pulserate). In some configurations, the radiation source 301 is adapted todeliver electromagnetic radiation in a “spot” like manner at UV orshorter wavelengths, such as wavelengths of 400 nm or lower, such as 355nm or lower, or even 300 nm or lower. In one example, the radiationsource 301 is configured to deliver electromagnetic radiation at mid-UVor shorter wavelengths (e.g., 248 or 266 nanometers (nm)), to theexposed region 231 at a wafer-laser-power of between about 0.5 and about2 milliWatt (mW), such as 1 mW and an illuminated area of between about0.1 and 10 μm².

However, in some non-inspection type configurations, such as where theprocess chamber 200 is adapted to perform a laser induced thermalprocessing technique on a substrate 210, the radiation source 301 mayoperate at a visible or IR wavelength, such as >800 nm or greater inorder to thermally process a substrate. In one example, the radiationsource 301 is configured to deliver electromagnetic radiation at avisible wavelength, to the exposed region 231 for much longer durationsand at a power level of between about 10 and about 1000 Watts (W). Inone example, the source 230 may be configured to deliver a beam ofenergy that has a power density of between about 10 kW/cm² and about 200kW/cm².

In another non-inspection type configuration, the process chamber 200 isadapted to perform a microwave source type thermal processing processes,the radiation source 301 can operate at a microwave frequency, such as600 MHz or greater, in order to thermally process a substrate. In oneexample, the source 230 may be configured to deliver a beam of microwaveenergy that has a power density of between about 1.5 W/cm² and about 2.5W/cm².

In some embodiments, the process chamber 200 may also include an opticalsubsystem 310 that includes an optical lens 311. In one configurationthe optical subsystem 310 is configured to deliver electromagneticradiation to the exposed region 231, so that the electromagneticradiation reflected or scattered from the surface of the substrate 210can be detected by the optional radiation detector 306 and used asreceived data in an inspection process. Alternately, the opticalsubsystem 310 is a radiation detector that is configured to detect theelectromagnetic radiation reflected or scattered from the surface of thesubstrate 210, due to the delivery of the radiation “A” provided fromthe source 230.

In some embodiments, the process chamber 200 may also include a fluiddelivery source assembly 450 that contains a source 451 that isconfigured to deliver a cooling fluid 452 to the exposed region 231(FIG. 4) to prevent the materials within the exposed region 231 frombeing changed by the exposure to the radiation “A” delivered from thesource 230. The cooling fluid 452 is cooled prior to exiting the source451 by use of one or more heat exchanging elements (not shown). Thecooling fluid 452 is generally delivered at a high flow velocity fromthe fluid delivery source assembly 450 to increase the convective heattransfer between the surface of the substrate and the cooling fluid 452.In one configuration, cooling fluid 452 includes a cooled gas, such as adry, inert and/or non-reactive gas, such as nitrogen (N₂), argon (Ar),helium (He), neon (Ne), krypton (Kr), xenon (Xe) or other type of gas,or combinations thereof to the exposed region 231.

In some embodiments, the process chamber 200 may also include a localizetemperature regulation source 460 that is adapted to heat and/or coolareas of the substrate surface during processing. In one example, thelocalize temperature regulation source 460 is used to pre-cool an areathat will be exposed to the radiation “A” or post-cool an area that wasexposed to the radiation “A” by delivering of a fluid to the surface ofthe substrate. While, in some configurations, the localize temperatureregulation source 460 may include a lamp or other similar device that isused to prevent the surface 213 of the substrate from in some casesundesirably reaching the temperature of the substrate supporting surface415 of the substrate chuck 410.

Processing Sequence Example

FIG. 5 illustrates a process sequence 500 that can be used to reduce theadverse effects of exposing portions of an integrated circuit (IC)device to various forms of radiation during one or more semiconductorfabrication operations. In general, the process sequence 500 includes areceive substrate operation 502, an optional pre-treat substrate process504, a semiconductor processing operation 506, and optional post-treatsubstrate process 508 and a remove substrate process operation 510. Atblock 502, the process sequence 500 starts with an external roboticdevice, or user, transferring a substrate into the processing region 211of a process chamber 200 (FIG. 2) through the sealable port 202. Atblock 502, the substrate may be positioned in or over the heatingstation 260 by use of the external robot. However, in cases where thesubsequent block 504 is not performed, the external robot may positionthe substrate 210 on or over the substrate support assembly 250. Afterreceiving the substrate 210, the process chamber 200 is then sealed byuse of the slit valve (not shown) positioned within the sealable port202. Then during block 502, and blocks 504-508, the pressure, gascomposition and/or gas flow rate within the processing region 211 isadjusted by use of the exhaust system 205, gas delivery system 206 andsystem controller 290 to achieve a desired environment within theprocess chamber 200. The environmental conditions in the processingregion 211 are typically adjusted by the system controller 290 toprevent the atmospheric contamination received while the sealable port202 was open from condensing on the surfaces of the subsequently cooledsubstrate 210 and the cooled substrate support assembly 250 components.

Next, at block 504, the substrate 210 is then optionally pre-processedbefore the substrate 210 is further processed during block 506. In thisblock, the substrate is positioned on the surface 261A of the heatingstation 260 so that the substrate can be cooled or heated to a desiredpre-processing temperature. In one example, as discussed above, thepre-processing temperature is less than room temperature, but greaterthan the dew point of the environment outside the process chamber. Afterperforming the operations in block 504, the substrate 210 is thentransferred from the heating station 260 to the substrate supportassembly 250 using the robotic device 270.

Next, at block 506, one or more semiconductor processing operations areperformed on the substrate 210 in the substrate support assembly 250.The semiconductor processing operation(s) performed during block 506 mayinclude the delivery of radiation to the surface of a substrate during adeposition, etching, ashing, annealing, inspection and/orpost-semiconductor processing operation, as discussed above. In someembodiments, the one or more semiconductor processing operationsincludes a non-contact optical inspection operation that is able todetermine some physical property, material property or othercompositional, dimensional or defect related attribute of the substrate.During block 506, the substrate 210 is positioned on a substratesupporting surface 415 of the support device 220 that has been cooled toa desired processing temperature, such as a temperature less than roomtemperature (e.g., −30 to −100° C.). In some embodiments, the substratesupporting surface 415 can be maintained at a specified lowertemperature during (e.g., −30 to −100° C.) during part of or entire timeof the exposure of the substrate 210 to radiation as described below.The substrate 210 is then “chucked” to the substrate supporting surface415 of the support device 220 and an amount of electromagnetic radiation“A” is delivered to an exposed region 231 of the surface of thesubstrate 210. It is believed that the techniques performed during block506 will be useful when the incident power level of the deliveredradiation “A” exceeds the threshold power level P_(T), as discussedabove. Thus, by use of the techniques described herein, the generatedradiation “A” can be delivered to the surface of the substrate withoutdamaging the exposed materials or material layers found in the exposedregions 231 by controlling the environment surrounding and temperatureof the substrate 210.

Next, at block 508, the substrate 210 is optionally post-processed afterblock 506 has been performed. Prior to or during block 508, thesubstrate 210 is transferred from the substrate support assembly 250 tothe heating station 260, using the robotic device 270. In block 508, thesubstrate may be positioned on the surface 261A of the heating station260 so that substrate can be heated to a desired post-processingtemperature. In one example, as discussed above, the post-processingtemperature is between about 10° C. and 50° C. In one non-limitingexample, the post-processing temperature is less than room temperature,but greater than the dew point of the environment outside the processchamber. The post-processing temperature can be greater than theprocessing temperature at which the supporting surface 415 wasmaintained during block 506 (i.e., the temperature −30 to −100° C.).

At block 510, an external robotic device, or user, removes the substrate210 from the processing region 211 of a process chamber 200. In thisprocess operation, the substrate may be removed from a position in orover the heating station 260 by use of the external robot, and theprocess chamber 200 may then be re-sealed by use of the slit valve inthe sealable port 202. During block 510, the pressure, gas compositionand/or gas flow rate within the processing region 211 may be adjusted toachieve a desired processing environment within the process chamber 200to prevent contamination received while the sealable port 202 was open,from condensing on the surfaces of the cooled substrate support assembly250 components.

One or more embodiments of the disclosure may be implemented as aprogram product for use with a computer system found within the systemcontroller 290. The program(s), or coded process sequences, of theprogram product define the functions of the various embodimentsdisclosed herein (including the methods described herein) and can becontained on a variety of computer-readable storage media. Illustrativecomputer-readable storage media include, but are not limited to: (i)non-writable storage media (e.g., read-only memory devices within acomputer such as CD-ROM disks readable by a CD-ROM drive, flash memory,ROM chips or any type of solid-state non-volatile semiconductor memory)on which information is permanently stored; and (ii) writable storagemedia (e.g., floppy disks within a diskette drive or hard-disk drive orany type of solid-state random-access semiconductor memory) on whichalterable information is stored.

While the foregoing is directed to embodiments of the disclosure, otherand further embodiments of the disclosure may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

The invention claimed is:
 1. A substrate inspection apparatus,comprising: a substrate support disposed within a processing region ofthe substrate inspection apparatus, wherein the substrate supportcomprises a substrate chuck that has a substrate supporting surface; aradiation source that is configured to inspect a substrate by deliveringradiation to a surface of a substrate disposed on the substratesupporting surface during an inspection process; a support assembly thatcomprises one or more actuators that are configured to translate thesubstrate support relative to the radiation source; a temperaturecontrol assembly that is in thermal communication with the substratesupporting surface, wherein the temperature control assembly isconfigured to cool the substrate supporting surface to a firsttemperature that is less than 20° C. during the inspection process; anda radiation detector configured to detect radiation reflected orscattered from a surface of a substrate that is disposed on thesubstrate supporting surface.
 2. The substrate inspection apparatus ofclaim 1, wherein the radiation source is configured to generateelectromagnetic radiation or an electron beam.
 3. The substrateinspection apparatus of claim 2, wherein the radiation source isconfigured to generate electromagnetic radiation at a wavelength ofbetween about 193 nm and 355 nm.
 4. The substrate inspection apparatusof claim 1, further comprising: an enclosure that comprises one or morewalls that define the processing region; and a thermal control devicethat has a substrate supporting surface that is disposed in theprocessing region, and is configured to maintain the substratesupporting surface of the thermal control device at a temperaturegreater than the first temperature.
 5. The substrate inspectionapparatus of claim 1, further comprising: an enclosure that comprisesone or more walls that define the processing region, wherein theenclosure is sealable during the inspection process to preventatmospheric contamination from entering the process region during theinspection process; and a thermal control device that has a substratesupporting surface that is disposed in the processing region, and isconfigured to maintain the substrate supporting surface of the thermalcontrol device at a temperature greater than a dew point of anatmospheric environment positioned in a region external to theprocessing region.
 6. The substrate inspection apparatus of claim 5,further comprising a gas source that is configured to deliver a dry gasto the processing region, wherein the dry gas comprises nitrogen (N₂),argon (Ar), helium (He), neon (Ne), krypton (Kr) or xenon (Xe).
 7. Thesubstrate inspection apparatus of claim 1, wherein the substrate chuckfurther comprises an electrostatic chuck that comprises a bias electrodeand a chucking power source.
 8. The substrate inspection apparatus ofclaim 7, wherein the substrate chuck further comprises one or moregrooves that are formed in the substrate supporting surface and areconfigured to receive a gas from a gas source.
 9. The substrateinspection apparatus of claim 1, further comprising: an objective lensthat is disposed between the radiation source and the substrate support.10. The substrate inspection apparatus of claim 9, wherein the objectivelens is disposed between the radiation detector and the substratesupport.
 11. A substrate inspection apparatus, comprising: a sealedenclosure that comprises a port that is selectively sealable to preventcontamination from entering a processing region formed therein during aninspection process; a substrate support disposed in the processingregion comprising a base having one or more channels; a radiation sourcethat is configured to inspect a substrate by delivering radiation to asubstrate disposed on the substrate supporting surface during theinspection process; a chiller coupled to the one or more channels; and aradiation detector configured to detect radiation reflected or scatteredfrom a surface of a substrate that is disposed on the substratesupporting surface.
 12. The substrate inspection apparatus of claim 11,wherein the chiller is configured to circulate a cooling fluid throughthe one or more channels during the inspection process.
 13. Thesubstrate inspection apparatus of claim 11, further comprising a supportassembly that comprises one or more actuators that are configured totranslate the substrate support relative to the radiation source. 14.The substrate inspection apparatus of claim 11, further comprising: anobjective lens that is disposed between the radiation source and thesubstrate support.
 15. The substrate inspection apparatus of claim 14,wherein the objective lens is disposed between the radiation detectorand the substrate support.
 16. A substrate inspection apparatus,comprising: an enclosure that comprises one or more walls that define aprocessing region; a substrate support disposed in the processingregion; a radiation source that is configured to inspect a substrate bydelivering radiation to a substrate disposed on the substrate supportingsurface during an inspection process, the substrate having a firstsurface including a patterned structure; a temperature regulation sourceconfigured to cool a localized area of the first surface without coolingother portions of the first surface; and a radiation detector configuredto detect radiation reflected or scattered from a surface of a substratethat is disposed on the substrate supporting surface.
 17. The substrateinspection apparatus of claim 16, wherein the temperature regulationsource is configured to cool the localized area of the first surfaceprior to exposure of the localized area to radiation during theinspection process.
 18. The substrate inspection apparatus of claim 16,further comprising a chiller, wherein the substrate support comprises abase including one or more channels coupled to the chiller.
 19. Thesubstrate inspection apparatus of claim 18, wherein the temperatureregulation source is configured to cool the substrate from above thesubstrate support.
 20. The substrate inspection apparatus of claim 16,further comprising: an objective lens that is disposed between theradiation source and the substrate support.